000
AXNT20 KNHC 131802
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE JAN 13 2015

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL  
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF 
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE 
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE 
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...ITCZ/MONSOON TROUGH...                                     
THE MONSOON TROUGH EXTENDS ACROSS THE GULF OF GUINEA TO 04N14W 
WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ CONTINUES WEST ACROSS 
THE ATLANTIC FROM 04N14W TO 03N31W TO THE COAST OF FRENCH 
GUIANA. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM N OF THE 
ITCZ BETWEEN 24W AND 45W. 
 
...DISCUSSION...

GULF OF MEXICO...                                               

A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM COASTAL WATERS OF 
NORTH CAROLINA SOUTHWARD ACROSS CUBA TO THE SW CARIBBEAN SEA. 
THIS TROUGH CONTINUES TO SUPPORT A FRONTAL SYSTEM ANALYZED AS A 
COLD FRONT ACROSS NORTHERN FLORIDA SW TO 29N82W 26N87W TO 24N91W 
WHERE IT TRANSITIONS TO A STATIONARY FRONT ALONG 21N95W TO THE 
BAY OF CAMPECHE NEAR 18N94W. OVER THE GULF...SHALLOW MOISTURE 
BEING ADVECTED FROM THE CARIBBEAN AND THE SW N ATLC WATERS ALONG 
WITH A DIFFLUENT ENVIRONMENT ALOFT SUPPORT SCATTERED SHOWERS W 
OF THE FRONTAL BOUNDARY EXCEPT FOR THE NW BASIN N OF 28N WHERE 
FOG IS BEING REPORTED. MODERATE TO FRESH NORTHERLY FLOW PERSISTS 
BEHIND THE FRONT WHILE LIGHTER NORTHEASTERLY TO EASTERLY FLOW 
DOMINATES EAST OF THE BOUNDARY. THE PORTION OF THE FRONT ACROSS 
THE BASIN WILL WEAKEN TONIGHT THROUGH WED MORNING LEAVING A 
SURFACE RIDGING AS THE DOMINANT FEATURE. 

CARIBBEAN SEA...                                                

RAINSHOWERS PERSIST ACROSS THE NW CARIBBEAN BEING ENHANCED BY 
MIDDLE-LEVEL DIFFLUENCE AND A SHARP UPPER-LEVEL TROUGH WITH BASE 
REACHING THE SW BASIN. TRADE WIND FLOW CONTINUES TO DIMINISH 
OVER THE CENTRAL AND EASTERN CARIBBEAN AS STRONG HIGH PRES N OF 
THE AREA HAS WEAKENED AND SHIFTED EAST. TRADES IN THESE REGIONS 
ARE 20-25 KT...DIMINISHING TO 15 KT BY WED MORNING. PASSING 
SHOWERS ARE NOTED ACROSS THE LESSER ANTILLES THROUGH PUERTO 
RICO. 

...HISPANIOLA...                                                 

SHALLOW MOISTURE EMBEDDED IN A SLIGHT TO GENTLE BREEZE CONTINUES 
TO DELIVER WEAK FAST MOVING SHOWERS ACROSS THE ISLAND. THESE 
SHOWERS WILL REMAIN POSSIBLE THROUGH TONIGHT WHEN A DRY AIRMASS 
STARTS TO MOVE ACROSS THE ISLAND. DRY AIR SUBSIDENCE ALOFT WILL 
PREVENT THE DEVELOPMENT OF DEEP CONVECTION. 

ATLANTIC OCEAN...

A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM COASTAL WATERS OF 
NORTH CAROLINA SOUTHWARD ACROSS CUBA TO THE SW CARIBBEAN SEA. 
THIS TROUGH CONTINUES TO SUPPORT A FRONTAL SYSTEM ANALYZED AS A 
COLD FRONT FROM 30N77W SW ACROSS NORTHERN FLORIDA FROM 29N81W TO 
28N82W THEN ACROSS THE GULF TO 24N91W WHERE IT TRANSITIONS TO A 
STATIONARY FRONT. TROUGHINESS ALOFT SUPPORT A SURFACE TROUGH 
ALONG 29N76W TO 23N80W. SCATTERED MODERATE CONVECTION AND TSTMS 
ARE WITHIN 120 NM EITHER SIDE OF ITS AXIS...INCLUDING THE 
NORTHERN BAHAMAS. ISOLATED SHOWERS ARE OVER THE REMAINDER 
BAHAMAS. AN UPPER LOW IS IN THE FAR E ATLC CENTERED NEAR THE 
CANARY ISLANDS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM THE 
CANARY ISLANDS NEAR 32N15W TO INLAND OVER THE WESTERN SAHARA TO 
SENEGAL. THE REMAINDER OF THE BASIN IS DOMINATED BY HIGH 
PRESSURE WITH A 1036 MB HIGH CENTERED OVER THE N CENTRAL ATLC 
NEAR 32N40W. THIS IS SUPPORTING A BROAD AREA OF FRESH TO STRONG 
TRADE WINDS ACROSS THE ATLC BASIN S OF 25N. THE ATLC SURFACE 
RIDGE WILL SHIFT E THROUGH TONIGHT. A WEAK FRONT WILL MOVE 
THROUGH THE NW WATERS TONIGHT...SLOWLY SHIFTING E AND 
DISSIPATING ACROSS THE CENTRAL ATLC WED. 

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR